Alright, let's work through 5129 times 3934 step by step
5129 × 3934 = 3934 × (5129)
+ 3934 × 9 giving us 35406
+ 3934 × 20 which equals 78680
+ 3934 × 100 that equals 393400
+ 3934 × 5000 which equals 19670000

= 20177486
